here is a simple Xpresso setup to create a switch between two materials without reaffecting it to the texture tag manually. Especially useful when working with proxy texture (or low resolution videos) to switch back to the high resolution one at render time.

Ever wished you could set presets for your tools such as the Knife or Weight Tool much like any parametric object?
Well, this is possible by creating a simple script for each preset you wish to create. Here is the step-by-step procedure.